It is widely recognized that there is a major problem with the spread of infectious agents from one place to the next, as people/animals and organisms touch one surface and another. Infectious agents include microbes (microorganisms), e.g. bacteria, fungi (including spores), viruses or prions. Contact—hence the word “contagious disease” is the most common way that pathogens can spread from one individual to another. This transmission of microbes present on the hands/skin/body of people/organisms, are transferred onto the surfaces of items such as door handles/door knobs/door push plates/door rails/door leavers/counters/work surfaces/sinks/taps/car handles/towel/rails/bath rails/sink rails/stair lift rails/banisters, to name but a very small selection of surfaces that are frequently touched/contacted by a large number of individuals, in a short space of time. Such surfaces are then touched by the hands/skin/body of other person/organisms and these microbes may be picked up or transmitted by this new individual. If the microbe enters the human body via an open skin surface, such as a wound, e.g. a cut/abrasion, or by oral contact, there is potential for infection. Infections include those of the skin and other tissues, the bloodstream, the lungs and the urinary tract. Once in the body system, these pathogens can also lead to a cold, flu, mumps/measles, conjunctivitis, diarrhoea, bronchitis, dermatological disorders, vomiting or sickness, for example.
This is a particular problem in hospitals and medical centres, where the transmission of nosocomial infections or Healthcare Associated Infections (HCAIs), e.g. methicillin-resistant Staphylococcus aureus (MRSA), clostridium difficile (C. diff), norovirus by surface contact is a major cause of illness.
Infection control typically involves the prevention and control of healthcare-associated infections in primary and community care. Hospitals take steps to prevent the transmission of HCAIs to avoid infecting patients. Measures to prevent the spread of microorganisms from one person to another involve isolation or infection control. The type of infection control or isolation required for any patient depends, inter alia, on the microorganism, where the microorganisms are found on/in an individual and the patient. The most important type of isolation required for MRSA is what is called “contact isolation”. This type of isolation requires everyone in contact with the patient to be very careful about hand washing after touching either the patient or anything in contact with the patient.
About 10% of infections in the UK's public hospitals have been estimated to be airborne. This means that approximately 90% of infections are therefore transmitted in other ways, such as through contact with surfaces and other individuals. A significant number of contact surfaces in hospitals and public buildings are vertical surfaces such as door touch plates.
Biosecurity is a term that covers the actions and measures needed to be taken to safeguard individuals from diseases caused by viral, bacterial and fungal infections. Biosecurity is essential against the fight of these contagious diseases. Thus, it is highly desirable to provide a means of reducing the spread of microorganisms, e.g. in, hospitals, (where surfaces are regularly touched by many people), doctors waiting rooms and doors, public houses including door handles and furniture, veterinary buildings and doors etc, as well as office equipment/computer keyboards/mice etc. A number of attempts have been made to address this issue as described for example in, U.S. Pat. No. 5,407,685, U.S. Pat. No. 5,882,667, U.S. Pat. No. 6,298,521, U.S. Pat. No. 6,863,960, EP2098664, FR2892025, GB2363075A, GB2436284A, GB2472188A, U.S. Pat. No. 4,832,942 , US published application US2002041824A1, and US published application US2005034270A1.
U.S. Pat. No. 6,821,325 describes a multi-surface antibacterial protective device comprising, an under layer of material and an over a layer of a permeable material and a cavity disposed between the two. The cavity houses an antibacterial solution. There is little or no control over the seepage of the antibacterial agent from the cavity and when a liquid is used in the cavity, settlement of the liquid to the bottom of the system occurs, particularly when it is oriented vertically in use. Failure to address settlement causes a variation in the amount of liquid delivered from top to bottom, which becomes more pronounced as the system is progressively emptied of solution. Clearly, such a variation in the delivery rate across the system is a major concern where the system is applied to walls and door plates.
Published International application WO2007135424A1 describes a surface mountable delivery device, which has a multi layer construction comprising a liquid permeable support layer adjacent to a porous reservoir layer, the porous reservoir layer being provided with a backing layer. The surface mountable delivery device may comprise of stickers, tapes, pads, tubes, socks, etc. The present invention seeks to address in part the shortcomings with the device of U.S. Pat. No. 6,821,325, whilst improvement has been achieved by the device disclosed in WO2007135424A1 there remains a need for further or alternative devices.
A number of prior art devices that have a discrete porous contact surface through which material may be discharged are problematic during use. When their contact surfaces are contacted or compressed by for example a human hand liquid or gel may be discharged through the majority of the contact surface, even where no actual contact has occurred. There is little control or localisation of material discharge. This results in discharge of material beyond that required to be discharged at the point of contact, where disinfectant is required. This can often result in liquid run-off or dripping from the surface of the device. This is wasteful of disinfectant and results in a need to replace the device more frequently than is desirable.
In addition a further problem with prior art devices is that significant liquid evaporation occurs during use as there is difficulty in controlling or preventing evaporation from porous contact surfaces. This is particularly problematic when the liquid or gel consists of a volatile material such as an alcohol, e.g. ethanol.